1. Field of the Invention
A method for regulating body weight by adding to food a liposome-encapsulated immunoglobulin against lipase.
2. Background of the Invention
The bulk of dietary lipid is triacylglycerol. In the gastrointestinal tract a portion is hydrolized to fatty acids and glycerol by lipases. The present invention relates to a method for decreasing the amount of body weight normally gained after eating food by administering liposome-encapsulated immunoglobulins against lipase, including polyclonal antibodies, monoclonal antibodies and genetically engineered fragments thereof.
Lipases are commercially available. They are obtained from a variety of natural sources including the pancreas and a number of bacteria, e.g., Candida rugosa, Chromobacterium and species of Pseudomonas. 
The production of anti-lipase antibodies can be accomplished by injecting animals, such as rodents or rabbits, with lipase and collecting the blood serum, which contains the antibody. However, this procedure is costly and invasive.
A general method for producing antibodies which is non-invasive and more economical is known. It has been observed that eggs contain 50-150 mg of various antibodies. When a hen is injected with a particular antigen, 10-20% of the antibody isolated from the eggs are specific to that antigen. Losch et al, J. Vet. Med. B. 33:609-619 (1986); Gassmann et al, Faseb J. 4:2528-2532 (1990). Chicken antibodies can be protected from stomach acidity and pepsin hydrolysis by encapsulating them within liposomes Shimuzu et al, Biosci. Biotech. Biochem. 57:1445-1449 (1993).